Automatic player piano



INVENTOI? 8 Y fiber/es [cf/Down Aug. 21, 192 8.

C F STODDARD AUTOMATIC PLAYER PIANO Filed June 1,, 1923 Patented Aug. 21, 1928.

UNITED STATES PATENTOFFICE.

CHARLES F. STODDARD. OF NEW. YORK. N. Y., ASSIGNOR TO AMERICAN PIANO COM PANY, OF NEW YORK, N. 1., A

CORPORATION or NEW JERSEY.

AUTOMATIC PLAYER PIANO.

Application filed June 1,

' This invention relates to automatic musiial instruments such as player pianos and pertains more particularly to automatic expression mechanisms and means for governing-tone intensities.

Among other objects, this invention is intended to provide apparatus capable of governing the energy used for sounding the notes ofthe instrument, and provides for that purpose means for obtaining very delicate ad- "iustment thereof, and therefore precision and iccnracy in tone intensities. For: purposes of illustration, the-accompanying drawings show one practical-embodiment of the invention; but as will appear to those skilled in the art, the invention is suitable of embodiment in various constructions and organizations other than the shown and'described herein. In the drawings: 'Figili is a semi-diagrannnatieillustration of a typical expression mechanism embodying the invention. T 'Fig. 2 is a sectional-viewof the improved 'valveconstruction. a

Referring to the drawings,-tl1e customary striker-pnenmatics and valve mechanismsare shown at 1. and are connected by the sticker 2 with the customary'wippen 3. Any suitable pneumatic construction may be used and none is therefore shown in detail. The striker pneumatics are connected with the tracker bar T 'by'mcans of the usual tracker tube 4 which may be vented to atmospherein the usual manner by means of the opening 5. Also connected with the striker pneumatics is the wind trunk 6 which is opcratively connected with the expression chest -7.- This expression chest is divided into the two sections 8 and9 by a longitudinal partition as shown. The upper section 8 is connected with a suitable source-of power by the wind trunk 10 and is therefore subjected to high exhaust. while the lower section -9, connected with the striker pneumatics, contains regulatedexhaust as will beset forth hereafter. A passage 11 is provided between the .sections '8 and 9, the effective opening of which is controlled by the valve 12. Obviously; the position of the valve 12 with respect to the passage 11, will determine playing intensities of the instrument. If the passage be restricted by the valve 12. softer tones will be played than if the opening be unre- 1923. Serial No. 642,749.

above mentioned patent.. These valve mecha nisms are connectedwith the tracker bar T-by tubes 63, 63'5-and 63" and the cancel valve is connected with the trackeiuby the tube 80. Smce there :is no invention in, these valve mechanisms over-that shown in my previous a patent, they will not be described in detail herein. The valve mechanisms A. B and C are operatively connected withthe expression pneumatles 36, 35. and34 by the-tubes 42,41

and 40 respectively. The fixed board 32 I forms a means on which the expression pneumat cs are supported, their movableleaves bevmg secured to the board 33 which is hinged at 17 in such way as to swing vertically. The

valve stem 13 passes loosely through the fixed board .32 and is connected-to the movable board by suitable means. The lower end of thevalve stem passes through the chest 7 and has mountedthereon the valve 12.

The operation of the expression pneumatics 34, 35 and36 is similar to that described in Patent No. 1,409,492 of March 14, 1922 and will not therefore be described in detail. It is sufficient to say merely that the valve mechanisms and expression pneumatics are opera-ted in such way as to cause the valve 12 to assume varying positions with relation to the opening 11, thus permitting varying quantities of air to be drawn from the regulated exhaust chest 9 through the opening 11 by the source-of power. Connected to the upper end of valve stem 13 by the eye 39 is the coil spring 37 which exerts an upward pull on the valve 12. The tension of this spring may remain substantially constant or it may be varied by movement of the pneumatic 38 to which the spring 37 is connected. The pneumatic 38 is provided with a fixed leaf 44 and a movable leaf 45. A controlling valve mechanism for the pneumatic 38 is provided which may be conveniently mounted on the fixed leaf thereof. Such mechanism is here designated generally by 108 and is operatively connected with the pneumatic by one end of the passage 106, the other end of which terminates in the valve chamber 107. This valve chamber-maybe provided; with a port- 109 to=atmosphere and' a'port -110'to an exhaust chamber 111, which chamber may be suitably. connected. with a sourceoi'exhaust. The valve 112,.mounted inchainber. lfi'li con: trols ports 109and 110, and isoperated as hereinafter described to controL the degreethediaphiagm chamber 114 isconiioctedwitli the-exhaust chamber 11=1=by'the'bleed 115.

The flow of air'in the-passage 106-is restricted-by two adj ustahle screws 1-19 and'lZO, the screw 120 being adjusted"to estrict the passage 106 less than the screw 1. 19. A bypass is provided aroundthe screw 119consistingof the passages 122-and 123; thus providing operating passages to t'lie-pneumatic38 of twodi flerentcapacities. The by-passis controlledhy a diaphragm and ralve123superposed over the diaphragm chambeu-124. This chamber is in-turn connected by a passage 125 with a valve chamher126. This chamber is provided with an opening'127'to atmosphere and anopening; 128 to the exhaustichamher 111'. Mounted therein is a valve 129'coutrolled by the diaphragm 1'30 superposed over diaphragnn chamber "131. This chamber is also operatively connected tothe tracker by means ofthe' duct 132 and tube 139. The valve.129 is normally maintained in lowered position hy'tlie' bleed.134. It willbe noted, however, that; valve 123 is normally maintained in. raised position because the chamber 126 is normallyopen. to atmospheric air.

Vhcn atmospheric airis admitted to the tube 138 through the tracker. the valve 112 will be lifted thus opening'the passage 106 to exhaust from the exhaust chamber 111. The pneumatic 38 therefore will tend. to collapse, the spcedotthe collapse being reduced however, because offlie restrictionimposcd by the screw 119. (lonvers'ely if the pneumatic 38 is collapsed. and tlie'tracker opening controllingtube 138 is then closed. the pneumatic will expand slowly aszatmospheric air is admitted past'the screw 119. IE however. wliilethe tube 138 is open, thetuhe 139 be opened'to atmospheric air. thevalve 129 will be. raised allowing suctionfrom the exhaust chamber 111 to lower the valve 123. thus opening the by-pass, and the restriction imposedLhv the screw 119willbe' of no effect.

The bellows 38 therefore will be collapsed at a greater rate of speed than before.

It is thus apparent that this valve mechanism provides two speeds of collapse for the bellows 38 and is of practicable importance in obtaining crescendo ellects, as 113513.150 been previously explained in'Patent No.- 1,409,492 of March 14, 1922.

The expression mechanisms above described operate on the, vznve 12. to variably restrict the opening between the sections 8 and 9, thus varying the amount of air exhausted from the player pneumatics. Since it is essential that. this restriction be delicately performed in order to secure in the player pneumatics the exact degrees of tension desired, it is desirable to provide a valve which willatall times maintain a proper cooperative-position with respect to its seat. or which, becoming displaced, will adjust itself; to pnoper cooperative position therewith. Ir'the valve 12 be fixedou the valvestem 13; a. slight bending or warping of the valvestem may cause the valve to seatimproperly. Means are therefore provided which: will permit.the= valve to assum'e'a position parallel to itsseat and properly hold the valve in this position.

The valve disk 20 is-mo unted on a spherical bearing member 21 through which there is an opening 22 sufiiciently large in diameter'to allow the disk'an'd bearing to be loose on the stem 13; On either side of'the disk 20 are placed the collars 23 and24, also on the stem 13, these collars being adjustably' held in fixed position by means of lock-screws 25 and Between the collar 24'and disk: 20 is placed an additional collar 26 having the opening 27 through it. The diameter of this opening-is also larger than'that of thetvalve stem so that this collar may' move laterally" with respect tothe stem. The purpose of the eollar'26; is to provide a hearing circle to cooperate with-the bearing eireleof eollar 23, and. by making the collar 26 so that it may move laterally with respect to the stem, to compensate forradial and angular errors in manufacture and assembly. The adjustment of the collars is such that the valve disk2O may be moved angularly with respect to its stem. but being once moved Will ordinarily retain that position.

In operation the disk 20. when lowered to a position such that it will seat, assumes a position parallel to its seat since. as explained, it is held more or less loosely between the collars. If, however, the valve should become accidentally displaced from causes such as warping of the chest due to atmospheric changes, or an accidentalbending of the valve stem. as soon'as it comes to av position of contact with its seat it is immediately readjusted to a position parallel therewith;

The practical importance. of this device will be appreciated. Expression devices-such as herein illustrated are designed'to giveext-remely quick and accurate regulation of tone intensities. In playing very low intensities, particu arly when the valve is nearly closed, it is necessary that it should maintain a position of exact adjustment with respect to its seat in order that the exact intensities may be reproduced by the player actions.

It is to be understood that this invention is not limited to the specific construction and organization described for illustration. On the contrary, the described apparatus may be variably changed, modified and reorganized without diverting from the scope of the invention as defined in the subjoined claims.

I claim as my invention:

1. A throttle valve for automatic expression mechanisms, comprising, in combination, a valve stem, a valve mounted loosely thereon having a rounded bearing surface through which the stem passes, a pair of collars fixed to said stem mounted on either side of said valve and cooperating with said bearing surface to prevent longitudinal movement of the valve relative to the stem while permitting relative angular movement therebetween.

2. A throttle valve for automatic expression mechanisms, comprising, in combination, a valve stem; a "alve thereon; cooperating collar means also thereon; and means whereby said valve may move to various positions of angular adjustment with respect to said stem between said collars.

3. A throttle valve for automatic expres sion mechanisms, comprising, in combination, a valve stem; a valve thereon; a pair of cooperating collar means also mounted thereon; bearing means on said valve; said collars being provided with sockets in which the valve bearing rotates.

4. A throttle valve for automatic expression mechanisms, comprising, in combination, a valve stem; a valve thereon; a pair of cooperating collar means also mounted thereon; bearing means on said valve; :1- third collar loosely mounted on said stem between the valve and one of said cooperating collars, said third collar and one of said cooperating collars being provided with sockets in which the valve bearing rotates.

5. A throttle valve for automatic expression mechanisms, comprising, in combination, a valve stem; a valve thereon comprising a valve disk and bearing; a pair of cooperating bearing means on said stem; and means whereby one of said means may be moved laterally.

In testimony whereof, I have signed my name to this specification this 24th day of May, 1923.

CHARLES F. STODDARD. 

